Adherence to antiretroviral medications is critically important for persons with HIV (PWHIV). The primary aim of this 5-year study based on social cognitive and self-efficacy theory proposes to compare the effect of two intervention groups (structured [ITs] and individualized [Tl]) relative to usual care on adherence to antiretroviral therapy over time. A sample of 300 PWHIV (plus 51 for attrition), taking antiretroviral therapy and without HIV dementia will be randomly assigned to one of three study arms. Ts will receive a 12 week structured telephone delivered intervention and a 3-month maintenance program; half will then be randomized to receive 3 boosters over the next 6 months. TI will receive a 12 week individualized telephone delivered intervention based on their self identified needs and a 3-month maintenance program; half will be randomized to receive 3 boosters over the next 6 months. The usual care group will receive their regular care. Data will be collected at baseline, post-treatment (3 months), post-maintenance (6 months), post-booster (12 months), and 6 months post-booster (18 months). Adherence will be assessed using electronic event monitors (primary measure), diaries, 4-day recall, the Self reported Medication-taking Scale, and missed appointments. Secondary aims will examine the effect of adherence on clinical response and quality of life. Exploratory aims will examine: 1) the mediating effect of self-efficacy on adherence, 2) the mediating effect of adherence on the relationship between self-efficacy and outcomes: clinical response and quality of life; 3) physiologic feedback (symptoms, perceived burden of medication regimen, substance abuse) and psychologic feedback (mood, personality characteristics, interpersonal relations, perceived stigma) as possible predictors of self-efficacy. Repeated measures analyses with specified contrasts will be used to test stated hypotheses (p less than or equal too .05, two-tailed). Longitudinal data analytic techniques will be used to examine the relationship between protocol assignment and adherence over time. A similar approach will be used for the secondary aims examining intervention effect on clinical response and quality of life. Exploratory aims will be examined using structural equation modeling.